Reduction of boron compounds.



FRANK J'. TONE, OF NIAGARA FALLS, NEW YbRK.

REDUCTION OF BORON COMPOUNDS.

No Drawing.

Specification of Letters Patent.

Application filed January 18, 1909.

Patented Aug. 20, 1912.

Serial No. 472,903.

To all whom it may concern:

Be it known that I, FRANK J. TONE, a citizen of the United States,residing at Niagara Falls, in the county of Niagara and State of NewYork, have invented a new and useful Improvement in the Reduction ofBoron Compounds, of which the following is a specification.

This invention relates to the reduction of boron compounds and themanufacture of boron alloys, and especially refers to the manufacture ofalloys of boron with iron. The reduction of the element boron hasheretofore ofiered many difficulties, inasmuch as it requires very hightemperatures, but owing to the volatility of boron compounds at hightemperatures it is difficult to accomplish a reduction withoutconsiderable loss of the ore.

My invention refers to a particular method of carrying out the processof reduction in an electric furnace which obviates these largevolatilization losses and enables one to obtain alloys of higher boroncontent and to operate with greater efficiency than has heretofore beenpossible.

I prefer to use as an ore of boron, colem anite, which is one of theores most easily available commercially and which consists principallyof calcium 'borate having the formula Ca,B,,O,,(5H O). The colemanite ispreferably first calcined to free'it from the combined water and then acharge is formed consisting of colemanite 50 parts, carbon or coke 17parts and iron oxid in the form of mill scale, 33 parts, theseprop0rtions of the ingredients being by weight. These materials arefirst ground to powder and then thoroughly mixed. The electric furnaceemployed for reduction is of the well known type with verticalelectrodes depending into the furnace pot or chamber. The chamber isformed of refractory material and preferably lined with carbon.

When the furnace is partially filled with charge and the current turnedon the calcium borate quickly fuses and unites with the iron oxidforming a fluid conductive bath. This bath acts as a conductor for thecurrent from one electrode to the other and serves as a resistor for thegeneration of the heat necessary to accomplish reduction.

lVhen the bath is sufficiently heated the carbon reduces the boron fromthe calcium borate, this reduction being the more easily-accomplished onaccount of the presence of the iron which is also simultaneouslyreduced. The boron-iron alloy formed settles to the bottom of thefurnace and as the bath is gradually depleted of boron and iron, morecharge is added. \Vhen the bath becomes too high in lime a part of it istapped out along with the alloy. New charge is then added and theprocess continued in a practically continuous manner.

I have found that by maintaining the bath as a resistance conductor andas the principal heating means, the great volatiliza tion losses whichoccur in other methods of operation are avoided.

I have particularly described the process as applied to the productionof alloys of boron and iron, but by substituting other ores in place ofiron, as for example copper, it is possible to obtain correspondingalloys of boron with these metals. It may also in certain cases bedesirable to add metalliferous material in reduced or metallic forminstead of, or in addition to, the ore.

Having now described my invention, I claim:-

1. The process of reducing boron compounds, consisting in forming afused bath of a mixture of boron compound, fluxing material, reducingagent and metalliferous material, inter-posing said bath as aresistance-conductor between electrodes, said bath forming the completecircuit between said electrodes, passing through it current sufficientto reduce the boron compound and metalliferous material to form boronalloy, but insufficient to reduce the fiuxing material, and collectingthe said alloy.

2. The process of making boron alloys, consisting in forming a fusedbath of a mixture of calcium borate, reducing agent and metalliferousmaterial, inter-posing said bath as a resistance-conductor betweenelectrodes, passing through it current sufficient to reduce the boronand metalliferous material to form boron alloy, but. insufficient toreduce the calcium, and collecting said alloy.

The process of making ferro-boron, consisting in forming a fused bath ofa \mi-xture of calcium borate, carbon and iron, In testimony whereof Ihave hereunto set iriterposgng said 1bath das a resistanfie-conmy hand.

ductor etweeli e ectro es 'passing t rough it current sufiicient toredilce the bgron and FRANK 3 5 alloy it with the iron formingferro-boron, Witnesses:

but insuflicient to reduce the calcium, and F. I. PIERCE,

collecting the ferro-Toeron. W. A. DWYER.

